Valve for steam-engines.



l. W. ADAMS & W. LEABH.

VALVE FOR STEAM ENGINES.

APPLICATION FILED Dec. 5. 1913.

Patented July 27', 1915.

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INVENITORSF lg, fim sflfms COLUMBIA PLANDGRAPII co., WASHINGTON. u, c.

J. W. ADAMS & W. LEACH.

VALVE FOR STEAM ENGINES.

APPLICATION FILED DEC. 5, 1913.

1,,425, Patented July 27, 1915.

4 SHEETS-SHEET 2- Fig.2

II e ll 0 III 1 c (j f2 8 WITNESSES- 2 INVENTORS.

5 5 /%z-mezau2iam.s e ZflaZi'e7"l3ea 7L I. w. ADAMS-6L w. LEACHL VALVEFOR STEAM ENGINES.

Km. 1 9 1 7H 2 y m J d w n m P APPLICATION FILED. DEC. 5, I913.

4' SHEETS-SHEET 3.

- IN cTawze-s Z4 Z; Z66)" VENTORS' MdlrZG GaCZ/ away J. W. ADAMS & W.LEACH. VALVE FOR STEAM ENGINES.

APPLICATION FILED use. 5, 1913.

' LIQ Patented July 27, 1915.

4 SHEETS-SHEET 4- I A A igfl.

WITNESSES.

INVEN TORS. (7&71ze6w, (Wants JAMES WALTER ADAMS AND WALTER LEACI-I, OFBRADFORD, ENGLAND.

VALVE FOR STEAM-ENGINES.

To all whom it may concern:

Be 1t known that we, JAMES WVALTER Annie and VALTER LEACH, Britishsubjects,

residing both at Bradford, county of York,

England, have invented certain new and useful Improvements in Valves forSteam-Engines, of which the following is a specification.

This invention relates to double beat or multiple beat valves foradmitting steam to steam engines. Valves of this character constructedwith the lower valve face of less area than the upper valve face so thatthe lower face of the valve may pass through the upper seat into itsposition on the lower seat have heretofore been coupled to a pistonsliding in a cylinder, the piston having one surface subject to thepressure of the steam and the other surface subject either to full steampressure or atmospheric pressure by means of an auxiliary valve co-axialwith the piston and main valve.

The present invention consists essentially in the special constructionand arrangement of parts for admitting steam to the cylinder of theauxiliary piston for balancing and operating the main valve and forproviding a cushion of steam above the piston to prevent shock. I

The invention will be fully described with reference to the accompanyingdrawings forming part of the specification.

Figure 1. is a diagram showing the invention applied to an ordinarycompound engine, the pipes c from the balancing cylinder of the highpressure valves being con nected to the intermediate steam pipe be tweenthe H. P. and L. P. cylinders. Fig. 2. is a diagram showing theinvention ap plied to a uniflow engine for which it is especiallysuitable. Fig. 3. is a sectional elevation through the valve and valvechest showing the invention applied thereto. Fig. 4. is an enlargeddetail section of balancing cylinder C and piston D. Fig. 5 is asectional elevation through the valve and valve chest showing thebalancing cylinder and piston with the piston valve for automaticallyopening and closing the main valve. Fig. 6 is an enlarged section ofauxiliary piston valve F in same position as in Fig. 5 on line y. y. y.Fig. 8. Fig. 7. is a section showing the reverse position of theauxiliary piston valve F on line a a m. Fig. 8. Fig. 8. is an invertedplan.

The valve chest A of the engine with valve seats a a, a steam port A andthe main Specification of Letters Patent. Patgnted July 2 7 1915Application filed December 5, 1913.

Serial No. 804,903.

valve B are constructed in the ordinary way. On the valve chest A wemount a balancing cylinder C with a balancing piston D working thereinand fitted on or connected to the spindle b of the main valve B. Thepiston D may be adjustable on the valve spindle and is secured theretoby locking nuts Z) or by cotters or other device, as in Fig. 5. Thebalancing cylinder C is placed preferably within and inelosed by thevalve chest as shown butit may be exterior thereto if desired, and isfitted with inlet ports 0 through which high pressure steam from thevalve chest A is admitted and also with exhaust ports 0 opening into anannular recess around the cylinder and connected by a pipe 0 to thelower limit of pressure such as the condenser or any part of the enginecylinder, intermediate pipe connecting the cyl nders or to theatmosphere, see Figs. 1 and 2. Instead of the inlet ports 0 merelyopening into the valve chest they may by a suitable pipe be connecteddirect with the steam boiler or other steam supply.

The balancing piston D is fitted preferably with three packing rings 03d and (Z to insulate the port and is formed with an annular groove (Zand ports (l which connect the top of the cylinder C with the inletports 0 and through them with the steam chest or other higher limit ofpressure. The ports (Z may be of any suitable shape and preferablyconnect with the annular groove (6 cut around the piston.

In the arrangement as shown and described with reference to Figs. 3 and4 the area of the balancing piston D is about equal to the excess inarea of the valve seat a over the valve seat a by which the out ofbalance of the main valve is corrected. By making the area of thebalancing piston D rather larger than the excess in area of the valveseat a over the valve seat a and alternately admitting steamat thehighand low limits of pressure-above the balancing piston the main valve maybe automatically opened and closed by the steam. I

Figs. 5 t0 8 refer to the arrangement in which the balancing piston D ismade to open and close the main valve B, thus forming a steam operatedvalve gear. The balancing cylinder will now be called the Open atingcylinder. Referring to these figures in the cylinder C of the operatinpiston D, ports 0 and 0 are provided'wfiich admit alternately the hi hand low limits of pressure to the top si e of the piston D, (it will benoted that the entry of port to the opoperating piston D. Above thebalancing pistonD and fitted to. the main valve spin-' dle-b is a dashpot piston J provided with 1 tle nut j.

of the main Inallift.

piston rings j and j this works'in the dash potcylinder G. -The exhaustfrom beneath the dash pot piston is controlled by means ofa valve fittedat, M in the usualway. The piston J is screwed on to the valve spindle band secured in position by the cas- Above the piston J anddistantfrom'it equal to the ordinary maximum lift valve is a washer Lfitted into a recess" in the dash pot cylinder G; acting on the top ofthis washer is a very strong spring H, which acts as a buffer spring andtakes up any shock should the lift of the main valve for any reasonexceed the nor- The. washer L also acts as a spring carrier for thesmall springs Z which are compressed between the top of the piston J andthe washer L thus insuring a cushioned contact and absence of noisebetween these two parts. Resting on the dash pot piston J is a springcarrier is which supports the ordinary dash pot spring K, the lattercloses the valve in the ordinary manner. r

p The balancing or operating cylinder C, piston D. and auxiliary valve Fare all placed within and inclosed by the steam chest A for cleanlinessand convenience.

' They may however be placed wholly outside the steam chest A at anyconvenient position, with the balancing or operating piston,

: upon,, or connected with the main valve spindle, and provided with anindependent steam supply at the H. P. limit of pressure and connected tothe exhaust or other L. P. limit of pressure.

As applied to an ordinary compound engine as in Fig. 1, the pipes 0 fromthe balancing cylinder C of the high pressure valves are carried to theintermediate steam pipe M connecting the high and low pressurecylinders. Thepipes from the balancingcylinder C of the low pressurevalves are connected direct to the condenser. As applied to a uniflowengine as in Fig. 2., for which itis particularly applicable the pipesofrom the top of the balancing cylinders are carried to the oppositesides of the main 'enginepiston by which the steam released from thebalancing cylinders is entrapped between the main piston and the B thebalancing its bottom position when the lower limit of square inches andis also acting upward on an area equal to the inside of the bottom valveseat say N square inches. This makes the valve out of balance in adownward direction equal to P lbs. absolute (MN) sq. in. and the area ofthe balancing piston must be so proportioned that (P])) Z: P (MN) if pbe the lower limit of pressure, and Z the area of the balancing piston.

In the above cases the main valve B will be exactly in balance whenshut. If it is desired to have the main valve B out of balance in adownward direction when shut this may be regulated to any desired degreeby reducing the area of the balancing piston D. If it is desired toplace the main valve- B out of balance in an upward direction when shut,this may be regulated to any desired degree by increasing the area ofthe balancing piston D.

Working description of F 2'9. 3.VVhen the main valve B is closed on itsseat, the balancing piston D in its lowest position and the spacebetween the top of the piston and cylinder in direct communication withthe lower limit of pressure the main valve B is out of balance in adownward direction while the balancing piston C is equally out ofbalance in an upward direction. This places the whole system in balance.The gear for opening the valves (which may be any ordinary gear) nowcomes into operation and lifts the main valve B from its seat a a at thesame time the balancing piston D moves upward in the balancing cylinderC and in this upward movement the top packing ring shuts off theconnection 0 and c to the lower limit of pressure while the middlepacking ring opens up the ports 0 admitting the higher limit of pressurethrough the ports (2* to the space above the balancing piston. We havenow the same pressure acting upward and downward on both the main valveand the balancing piston therefore the whole sytem is in balance againand ready for the operating gear to close the valve. On closing the mainvalve piston D is again moved to pressure is gradually opened to thebalancing cylinder and the connection to the higher limit of pressureshut off thus again putting the valve in equilibrium ready for the cycleof operations to be repeated.

W orkz'ng description of F 7198. 5 to 8.The

main valve B is shown in its closed position. The auxiliary valve F hasjust been moved to its lowest position (by means of the operating gearwhich in the drawing is shown as a cam gear but may be replaced byeccentric, trip, or any other gear deriving its motion from the crankshaft of the engine) thereby opening up the top of the balancingcylinder through ports 0, 7, e and e (see Fig. 6) to the L. P. limit andclosing off the ports 0 and f (Fig. 5) to the H. P. limit. The pressurein the steam chest A now acts upon the underside of the operating pistonD (which has an area in excess of the out of balance area of the mainvalve) and raises it against the. resistance of the L. P. limit abovethe piston D causing the main valve B to open. The main valve willremain open until the auxiliary valve F is moved to its top position,(Fig. 7) thereby cutting off or closinglthe ports 0 f 6 and 6 (Figs. 5and 6) to t e L. P. limit and opening up ports f and c (Fig. 7 to the H.P. limit from the steam chest. This places the balancing piston D inequilibrium and the spring II closes the main valve 13. The valve B nowremains out of balance in a downward direction (thus insuring steamtightness throughout the whole expansion stroke and the greater part ofthe return stroke) until the point of opening when the auxiliary valve Fis again moved to its lowest position and the cycle of operations isrepeated. As soon as the main valve leaves its seat it is placed inequilibrium, therefore the upward pressure on the piston D will causethe valve, piston and spindle to travel upward with a rapidly increasingvelocity and momentum. This is resisted and overcome by the compressionof the L. P. limit of pressure inclosed in the space between the top ofthe balancing piston and the cylinder after the piston ring d has shutoff the port 0 to the L. P. limit (this is done immediately the pistonmoves up.) The pressure of steam left above the balancing piston and theamount of cushioning can be regulated to any desired amount, by means ofa valve controlling the port 6. In case the compression is notsufficient to bring the valve and spindle to rest, the dash pot piston Jcomes into contact with the large buffer spring H, which thus acts as asafety device to prevent the piston D coming in contact with the top ofthe cylinder C.

The whole of the operating gear can be made exceedingly light on accountof the fact that the auxiliary valve is balanced and the force exertedby the cam N on the roller 11. is simply that required to overcome thefriction of the auxiliary valve F.

IVhat we claim as our invention and de sire to protect by Letters Patentis:-

1. In a double beat or multiple beat drop valve, the combination of acylinder, and a piston connected to the valve and working in saidcylinder, the cylinder having a port for admitting the high and lowlimits of pressure thereto above the piston, the piston operating toclose said port and cut off the low pressure steam before completing itsstroke, leaving a cushion of steam at the top of the piston.

2. In a steam engine, the combination with a valve, of a cylinder, :1.dashpot piston connected to the stem of said valve and operating in saidcylinder, a spring acting on the dash-pot piston, and a cushioningspring normally inactive but operative to yieldingly resist over-motionin the opening of the valve.

In a double beat or multiple beat drop valve the combination with thevalve, the valve chamber and the valve seat, of a balancing or operatingcylinder provided with steam ports, a balancing or operating pistontherein connected with the valve, and an auxiliary valve and Valvechamber to control the admission of steam of high or low pressure to thebalancing or operating cylinder.

4. In a double beat or multiple beat drop valve the combination with thevalve, the valve chamber and the valve seat of a balancing or operatingcylinder provided with steam ports a balancing or operating pistontherein, connected with the valve, and an auxiliary valve and valvechamber to control the admission of steam of high or low pressure to thebalancing or operating cylinder, and means for operating the auxiliaryvalve.

5. In a double beat or multiple beat drop valve the combination with thevalve, the

valve chamber and the valve seat of a balancing or operating cylinderprovided with steam ports a balancing or operating piston thereinconnected with the valve, an auxiliary valve or valve chamber to controlthe admission of steam to the balancing or operating cylinder and a dashpot piston and buffer spring to prevent the balancing pist'on coming incontact with the top of its cylinder.

In testimony whereof we have hereunto set our hands in presence of twosubscribing witnesses.

JAMES WALTER ADAMS. IVALTEB LEAUI'I.

Witnesses:

HARRY L. KrrsoN, ROBERT TARR.

Gopies of this patent may be obtained for five cents each, by addressingthe Gommissioner of Patents Washington, D. G4

